Understanding the benefits of Windows Azure geo-redundancy in Australia

The Windows Azure family has been extended with deployment regions in Australia. The deployment regions are paired for geo-redundancy and in Australia are located in the New South Wales and Victoria sub-regions.

Why is geo-redundancy important ?

Windows Azure Storage is an important service that underpins a number of other Windows Azure services – Blob Storage, Table Storage, and Virtual Machine (OS and Data Volumes).

Geo-replication is enabled by default in Windows Azure Storage and provides the highest level of storage durability. Data is asynchronously replicated from your primary location to a secondary location within the same region. These locations are guaranteed to be at least 400kms apart to ensure that data durability across catastrophic events.

The following picture shows the New South Wales and Victoria sub-regions within the Australia geographical region. Here the NSW deployment region is the primary location and is asynchronously replicating data to the Victoria deployment region which is the secondary location.

In the event of a catastrophic event in the primary location where the primary location cannot be restored, all traffic will be failed over to the geo-replicated secondary location. This ensures business continuity.

What about redundancy within the deployment region ?

Within each deployment region there is an additional layer of redundancy. All data is synchronously replicated to 3 different storage nodes across 3 separate fault and upgrade domains. This allows each deployment region to recover from common issues such as disk, node or rack failure.

The following picture demonstrates the 3 copies across 3 separate racks and the creation of a new copy after the failure of a storage node.

When geo-replication is enabled, you will effectively have 6 copies of your data distributed across 2 geo-graphically dispersed deployment regions. The multiple layers and mechanisms ensuring highly durable data will provide business continuity across a number of scenarios.

How do these new deployment regions affect Australian businesses ?

The most obvious answers would be reduced latency and data storage within Australia.

Even though a Windows Azure CDN has been available out of Sydney for a while, it has only offered lower latency on Blob Storage for very specific read-only workloads. With an Australian region available now, lower latency is available to a wider range of Windows Azure services and this will benefit Australian businesses utilising the Windows Azure platform.

Content in Blob Storage that is produced and consumed within the local Australian market will benefit from the lower latency. A more compelling case can now also be made for cloud integrated storage solutions such as StorSimple. Those customers within Australia that have regulatory pressures preventing them from storing data outside of Australia will also be heartened and this announcement should remove this hurdle.